JWs teach that god is love and JWs are taught that they must go out and proclaim the good news of the kingdom to all the nation's then the end would come. Of course JWs are also taught that they are the only ones that will survive the big A and if others don't join they will die. Well here's the delusion or one of many in all this, as we can see from other threads and the internet, every religion indoctrinates their members so they believe what their taught just as strongly as a JW. So talking to someone at their door for a minute or two in most cases does nothing to convince someone to think about leaving their faith for another.
So the obvious and only way to fix this would be if god himself made miracles happen as a way to convince the people to change but he does nothing. Instead as we are taught he's going to just kill everyone, yet hes still a loving God. I think this would fit in to the definition of a delusion.